VIVANA Release Notes
VIVANA 4.28.0 (20240626)
VIVANA 4.28.0 Input changes
SNcurve thickness correction input
The reference thickness, TREF
, and the exponent, KEXP
, for
thickness correction must either both be zero, no thickness
correction, or both positive, thickness correction included.
KEXP
was previously dummy if TREF
was zero.
Input files where only one of these is zero must be modified. 
VIVANA 4.26.3 (20231107)
VIVANA 4.26.3 Corrected errors
Structural damping from file and retry option
Structural damping from file is an additional modelling option that is only available for NewtonRaphson response iterations. If the option to try both response iteration methods is on, the Fixed point method will be used if the NewtonRaphson method does not converge. This will give incorrect results as the damping from file is not included. An error check has been added.
Potential error since the retry option was made available in VIVANA 4.22.0.
VIVANA 4.26.3 Known issues
Analysis with CF and IL loading without IL added mass iterations
Frequency domain VIV with crossflow and inline loading calculated without added mass iteration for inline response frequencies gives zero inline response. This is incorrect and will be corrected in the future.
Normally, the inline added mass is adjusted to obtain an inline eigenfrequency that is twice the crossflow response frequency. This is done for all crossflow response frequencies. This is timeconsuming and is not always successful.
This inline added mass iteration is skipped if the crossflow added mass property is given for a single nondimensional frequency for all segments. The inline response frequency will be twice the crossflow response frequency, but will not be an eigenfrequency. The inline response is therefore expected to be small, but should not be zero.
VIVANA 4.26.3 Known issues
Analysis with CF and IL loading without IL added mass iterations
Frequency domain VIV with crossflow and inline loading calculated without added mass iteration for inline response frequencies gives zero inline response. This is incorrect and will be corrected in the future.
Normally, the inline added mass is adjusted to obtain an inline eigenfrequency that is twice the crossflow response frequency. This is done for all crossflow response frequencies. This is timeconsuming and is not always successful.
This inline added mass iteration is skipped if the crossflow added mass property is given for a single nondimensional frequency for all segments. The inline response frequency will be twice the crossflow response frequency, but will not be an eigenfrequency. The inline response is therefore expected to be small, but should not be zero.
VIVANA 4.26.0 (20230612)
VIVANA 4.26.0 New / improved functionality
Eigenvalue analysis
The eigenvalue solver has been replaced by a more numerically robust code. No significant changes are expected for acceptable eigenvalues. The reported mode shapes may be mirrored. Also, the order of mode shapes may be changed if there are multiple identical eigen values.
The user input to the initial eigenvalue analysis has been simplified. Vivana input files for standalone analysis must therefore be modified. The input file version at the top of the input file must be updated to 4.25.3 or higher.
VIVANA licensing
VIVANA
is licensemanaged using the FLEXlm / FLEXlnet software license
management system. If you want VIVANA
to be used from any networked
computer on your site, you must run a license manager on a server in
your network. Alternatively, VIVANA
may be run on a single computer
using a standalone license file.
Please note that version 4.2 and higher requires a licence file with a feature version that is equal or larger than the link date.
In order to issue a server license or a standalone license file, SINTEF Ocean or DNV GL needs the following info on your server:

License type (server or standalone)

Operating system and version (Windows 10, Windows 7, and Linux currently supported)

MAC address / FLEXlm hosted of the computer.
Your ITstaff is probably already familiar with this procedure as FLEXlm is used by a large number of other applications (e.g. Matlab).
VIVANA version numbers
The version number consists of three numbers separated by periods, e.g. 4.16.0. The two first are the version. The third is updated for each subsequent (bug fix) release.
Even numbered versions, e.g. 4.14, 4.16, are reserved for official versions.
Odd numbered versions, e.g. 4.15, 4.17, are reserved for development versions. The next official release will therefore be 4.26.
VIVANA 4.24.0 (20221004)
VIVANA 4.24.0 New / improved functionality
Bilinear SNcurves / twoslope SNcurves
Fatigue in frequency domain using Rayleigh distribution can now be calculated using bilinear SNcurves.
Allow SIMO bodies and bar elements in VIVANA analyses
The system may now include SIMO bodies. The mass and stiffness of the SIMO body elements will be included, but there will be no VIV loads on them.
Bar elements may be included in the system. VIV loads will only be applied if the system does not contain any beam elements.
Note that these new modelling features are under development.
VIVANA 4.24.0 Corrected errors
Correct force calculation for branching systems
Corrected an error in the calculation of element forces using stiffness for systems with branches. The calculation was incorrect for elements whose end nodes were not sequentially numbered. This will occur only in systems with branches.
Error in VIVANA drag amplification calculation for time sharing.
The standard deviation of the response used to calculate the drag amplification factor was calculated assuming that all response frequencies act simultaneously. This is corrected.
The standard deviation of the response on the _vivana.mpf file was correctly calculated 
Longstanding error.
VIVANA 4.22.0 (20220225)
VIVANA 4.22.0 New / improved functionality
Unique identification of response frequencies in MatrixPlot legends
Both the response frequency number and the response frequency are now included in the MatrixPlot legends for matrices with results for multiple frequencies. This is done to ensure a unique identification of each response frequency even if some response frequencies are similar enough to be printed identically.
The response frequency number is now included as the first column of the convergence summary table on the _vivana.mpf file.
The spelling of summary is corrected on the _vivana.mpf file.
Specification of crosssections for fatigue calculations
A group of segments and elements can now be selected using ALL
for
fatigue calculations. This means that  All segments in a line can be
selected  All elements in a selected line and segment can be selected
Allow crosssections to be specified for fatigue calculated from Rayleigh distributed stress cycles so that stress concentration factors (SCFs) may be specified.
Option to retry failed response iterations
An option to retry failed response iterations has been added. If selected, the other of the two response iteration methods will be tried if the response iterations do not converge with the specified method.
If neither method converges, the results from the best iteration in the second method tried will be used.
VIVANA 4.20.4 (2021????)
Bugfix release of VIVANA
4.20
VIVANA 4.20.4 New / improved functionality
Improved transition to constant added mass
An optional transition to constant added mass for higher modes was introduced in VIVANA 4.20.0. The transition is specified by the first and last active mode number for the transition. Specifying a transition from mode 0 to mode 0 will now give the same reduction in calculations as specifying mode 0 to mode 1.
No change in results, but improvement in computational time.
VIVANA 4.20.0 (20210407)
Initial internal release of VIVANA
4.20.
VIVANA 4.20.0 New / improved functionality
Print of curvature time series
Time series of curvature are now also available for cases with nonlinear bending stiffness. Calculation of forces, stress and fatigue damage will be skipped.
Previously, this gave an error exit.
A warning is printed to the resfile if nonlinear bending stiffness is found.
Optional transition to constant added mass for higher modes
The option for a smooth transition from frequencydependent added mass for lower modes to constant, stillwater added mass for higher modes has been implemented.
The transition zone is given by the input parameters ITRANS_LOW, the last mode number for which the full frequencydependent added mass curves and ITRANS_UP, the first mode number for which the constant stillwater added mass will be used. The mode number refers to the modes in the active VIV direction. In the transition region, a linear interpolation is used between the frequency dependent added mass and the constant stillwater added mass.
At present, the default values cause the added mass to be taken from the selected curves for all modes.
Flex joint on intermediate line segments
If a flex joint is applied on the ends of intermediate line segments, the response will inconsisent on the element adjacent to the flex joint.
VIVANA 4.18.1 (2020????)
Bugfix release of VIVANA
4.18.
VIVANA 4.18.1 New / improved functionality
Improve initial response estimate
The initial response estimate is improved by including nodal rotations in addition to translations.
This gives improved convergence for cases with curvaturedependent damping levels. Minor changes for other cases with NewtonRaphson iterations. No change for cases with fixed point iterations.
VIVANA 4.18.0 (20200323)
Initial release VIVANA
4.18.
VIVANA 4.18.0 New / improved functionality
Responsedependent structural damping specified in VIVANA
The data group STRUctural DAMPing SPECification allows additional material and slip damping to be specified for some or all segments in the system. This structural damping is read from separate files and is applied in addition to the relative structural damping level given by RELDAM. The structural damping is given as a function of the response curvature and is therefore updated during the response iterations.
At present, the calculated additional damping for an element is added using the total element stiffness matrix. Axial and torsional degrees of freedom will therefore also be damped.
NewtonRaphson response iterations must be used; i.e. IFRIT = 2.
Include crosssectional damping specified in INPMOD
Stiffnessproportional crosssectional damping specified in INPMOD will now be included in VIVANA. Like the seafloor damping, the crosssectional damping will come in addition to the relative damping specified in VIVANA. The damping will never be decreased under the level specified in VIVANA.
Currently, the stiffnessproportional damping coefficients must be identical for axial, torsional and bending displacements. Additional crosssectional damping may not be applied to elements that have boundary conditions in skew or vessel coordinate systems.
Choice of method for generating random numbers
The algorithm for generating pseudorandom numbers may be selected by the user. The choice of random number generator will apply to:  generation of stress time series for fatigue calculations using the Rainflow method.  output of curvature time series consistent with the stress time series generated for the Rainflow method.
VIVANA 4.16.0 (20190506)
VIVANA 4.14.0 (20181101)
VIVANA 4.12.2
VIVANA 4.12.2 Corrected errors
Userdefined added mass for inline VIV
The default inline added mass curves were used even if userdefined added mass curves were given.
Userdefined inline added mass for combined crossflow and inline VIV
If userdefined inline added mass was specified, the crossflow added mass was used if it also was specified by userdefined curves. If default crossflow added mass curves were specified, incorrect accessing could give program termination or possibly incorrect results.
For IRSTYP=3; combined crossflow and inline VIV; the inline added mass is used in the initial eigenvalue analysis for the inline response frequencies. These frequencies are used as the starting values if inline frequency iterations are performed. If not, the calculated initial mode shapes are used to establish initial response estimates for the response iterations.
VIVANA 4.12.0
VIVANA 4.12.0 New / improved functionality
Print of tension and curvature time series
The input parameter TSIOPPR for print of tension and curvature time series has been reactivated for concurrent response frequencies; IOPTSH = 0.
Element stress concentration factors can be given
The stress and fatigue damage can be estimated using element dependent stress concentration factors. Note that the stress is calculated using default stress concentration factors for the other elements.
Avoid ILfrequency iteration for combined crossflow and inline VIV
The inline frequency iteration for combined crossflow and inline VIV can now optionally be avoided. This is done by defining the constant added mass by a single value.
If IRSTYP=3 (Combined crossflow and inline VIV) and constant added mass curve with NAMPT=1 is used for all sections, no IL frequency iteration is performed. The IL frequency is set to twice the CF frequency and the inline added mass is not adjusted.
Calculation of fatigue contributions
The relative duration; i.e. the probability; of the current condition; may now be specified in the VIVRESPONSE FATIGUE DAMAGE data group. If a nonzero relative duration is given, the fatigue damage contributions will be found as the calculated fatigue damage scaled by the relative duration. The fatigue contributions will be written to the _vivana.mpf file in addition to the calculated fatigue damage.
VIVANA 4.12.0 Corrected errors
VIV analysis with flexjoint
Corrected a longstanding error in stiffness contributions from flexjoints. The error could cause incorrect response for systems with flexjoints.
Also corrected in VIVANA 4.10.5.
Corrected some default values
Some input parameters were not set to their default value if input was not given by the user. This has been corrected.
Corrected the line length used in result presentation
The accumulated line length used in result presentation is now calculated from the actual stressfree segment lengths given in the line type definition in INPMOD; i.e. parameter SLGTH0 if it is given, otherwise SLGTH.
The line length is used for results on the _vivana.mpf file and for fatigue damage on the _vivana.res file. Previously, the line length in VIVANA was calculated from the final static nodal coordinates.
Significant changes are expected for cases in which all elements do not follow each other sequentially.
The change in line length will be small for cases without  segment length change; initially prestressed segments in STAMOD or segment length variation in DYNMOD  length changes due to temperature or pressure changes  element length modification for elements on / leaving a winch  large static elongation / compression (VIVANA and OUTMOD)
Correct calculation of 1D modes for complicated systems
A longstanding error in the calculation of mode shapes in the VIV active plane has been corrected. The error occurred for systems where the elements were not all in a single row one after the other. The error could cause incorrect ranking of response frequencies or program termination.
No consequence for simple systems where all elements are in a row one after the other.
Error since VIVANA
4.0. Also corrected in VIVANA
4.10.2.
VIVANA 4.10.0
Initial release of VIVANA
4.10.x.
VIVANA 4.10.0 Input changes
Input files used in version 4.8 can be used unchanged.
Input for new functionality is described in the User Manual.
VIVANA 4.10.0 New / improved functionality
Userdefined inline coefficients
Userdefined excitation, added mass and excitation zone coefficients may
now be given for pure inline loading, IRSTYP
= 2.
Userdefined excitation coefficients in table format
Userdefined excitation curves in table format may now be given for
combined crossflow and inline loading, IRSTYP
= 3.
Results on _vivana.mpf file
The initial response estimate is written to the _vivana.mpf file for all response frequencies.
Final results are written even if the response is below the limit.
Avoid duplication of matrices when response iterations have not converged and the last iteration is identified as the best.
For combined crossflow and inline VIV loads (IRSTYP
= 3) and
IPRINT
= 5, write both CF and IL response for all iterations.
For IOPTSH = 1
; consecutive response frequencies or timesharing; the
relative duration of each response frequency is now reported on the
_vivana.mpf file.
Reporting of response calculation convergence
A warning is printed on the _vivana.res file if any of the response calculations did not converge. Detailed information about the response convergence is then also written on the _vivana.res file.
Detailed information about the response convergence is written on the _vivana.mpf file.
The matrix All response iterations converged? with three values is also
written on the _vivana.mpf file. The first two numbers are 1 if all
response calculations have converged and 0 if any did not converge. The
third is 1 if all the response calculations with significant response
converged, 0 if any of these did not. The key for the two Y
values
give the number of response calculations that converged.
VINANA 4.8
VIVANA 4.8 Corrected errors
Error in seafloor damping in VIVANA
Seafloor damping may be specified for analyses using the 3D seafloor
formulation; i.e. IBOR3D = 1
or IBTANG = 1
. A longstanding error
has caused this damping to be incorrectly applied in VIVANA
since 3.6.
No error if the damping was less than the damping specified in VIVANA
.
The error has been corrected.
Corrected in VIVANA
4.8.7
Linux binary files
The record length of the binary files was set to four times the correct
value. The .ffi, .sam, .raf, and .bin files were therefore four time
their necessary size. The .bin files from STAMOD
were not comparable
with their documentation and preexisting tools for reading them.
Error since 4.8.0. Corrected in VIVANA
4.8.3
VIVANA 4.8 New / improved functionality
New Linux release
The new Linux release of SIMO
, RIFLEX
and VIVANA
is 64bit and
solves several issues. Unfortunately, this means that 32bit Linux
operating systems are no longer supported.

Supports more than the 32bit imposed limit of 2 GB of RAM

No need to install 32bit support libraries separately

No special considerations are needed for writing output files larger than 2 GB

The necessary runtime libraries are included in the installation package and no special consideration is needed for installation; the package is now fully relocatable
The package has been tested on the following Linux distributions:

CentOS 7

Ubuntu 14.04 LTS

Linux Mint 17
VIVANA 4.4
VIVANA 4.4 Corrected errors
Specification of hydrodynamic coefficients
Hydrodynamic properties are specified in the data group SECTION PROPERTY
SPECIFICATION. VIVANA
will now check that coefficients are specified
for all segments in the model. This was not previously checked and could
give errors.
Corrected radius of gyration for CRS0 cross section
The radius of gyration for CRS0 cross sections has been corrected in
RIFLEX
. This concerns both CRS0 cross sections explicitly specified in
the model as well as CRS0 cross sections generated for a stress joint
specification. Please see the RIFLEX
4.4.1 Release Notes for details.
For most cases, the correction is not expected to cause significant changes in the response. For some cases, however, the correction may lead to changes in convergence and estimated response. Note that changes in estimated stress are exponentially increased by the slope of the SNcurve to changes in estimated fatigue damage. With a slope of 4.0 in the SN curve, a 2 % increase in stress will give an 8 % increase in estimated fatigue damage.
Corrected in VIVANA
4.4.1.
Nonunique matrix titles
If more than 20 response frequencies contribute to the response, the
plots of response amplitude, curvature, axial force, bending moment and
stress are split into several matrices on the _vivana.mpf
file. These
matrices will now have unique names. Truncation of the legends is now
avoided, so all frequencies will be plotted.
These corrections aid examining and extracting intermediate results. No change to final results; e.g. fatigue damage.
Non–unique matrix names may still occur if the response iterations do not converge and the last iteration is identified as giving the best response estimate.
Corrected in VIVANA
4.4.2.
VIVANA 4.2
VIVANA 4.2 Input changes
INPMOD and STAMOD input change
INPMOD
and STAMOD
4.0 input files may be used unchanged.
Input for new functionality is described in the RIFLEX
User Manual.
Input file version identifier
The input file version CHVERS
must now be given in the data group
VIVANA CONTROL INFORMATION at the beginning of the input file:
VIVANA CONTROL INFORMATION 4.0
At present CHVERS
must be 4.0.0 or higher.
Input to response analysis reorganized
The input parameters SCAINI
, REXPAL
and REXPAH
have been added to the data group RESPONSE ANALYSIS PARAMETERS:
RESPONSE ANALYSIS PARAMETERS ' reldam iopfrc iprint 0.010 1 1 ' ifrit max_niter ilim conlim scaini 2 40 AMPNOR 0.0005 0.5 ' ioptsh nuddis adlim rexpal rexpah 1 0 / 0.2 1.0
SCAINI
specifies the scaling of the initial response estimate. The
default value is 0.5, giving the same initial response estimate as in
VIVANA
4.0.
REXPAL
and REXPAH
are used to limit the number of response
frequencies. The default values are 0.0, i.e. no cutoff applied.
Input to fatigue analysis reorganized
A new option for the fatigue analysis IOPDAT has been added to the data
group VIVRESPONSE FATIGUE DAMAGE. For IOPDAT
= 3 the fatigue damage is
calculated directly from the harmonic stress amplitudes. Valid for
singlefrequency response only.
VIVRESPONSE FATIGUE DAMAGE ' iopfat nsect npcs ioppr tsioppr chtsprn 3 0 4 0 ' dscfa dscfy dscfz asi wsti thi rfact 1.0 1.0 1.0 0.030449981 0.003549035 / 0.001
VIVANA 4.2 New functionality
Option to limit the number of concurrent response frequencies
The new input parameters REXPAL
and REXPAH
allow the user to limit
the number of response frequencies. Response frequencies with excitation
parameter below the userspecified cutoff values are omitted. The
cutoff values are given as fractions of the highest excitation
parameter value, which is for the dominating frequency. Separate cutoff
values are given for response frequencies below and above the dominating
frequency.
At present, the default values are zero so no response frequencies will
be omitted. Specifying REXPAL
= 0.2 and REXPAH
= 1.0 will omit all
response frequencies above the dominating frequency and those below that
have excitation parameters of less than 20 % of the peak value. This
agrees well with experiments with linearly sheared current and a
constant diameter.
User input for scaling the initial response estimate
The user may give a scaling factor for the initial response estimate or, alternatively, the scaling may be based on the excitation curves in the excitation zone. The input is added to aid in analyses with convergence problems. For some cases, the scaling based on the excitation curves gives improved convergence. The default is to scale so that the maximum amplitude is 0.5 average diameters, corresponding to the builtin values in previous versions.
Direct calculation of fatigue from constant stress amplitudes
Add option IOPFAT
= 3 for direct calculation of fatigue assuming
constant stress amplitudes. This option may be used for singlefrequency
response only. Currently available for IRSTYP
= 1 or 2; i.e. pure CF
loading; or pure IL loading; and a single response frequency.